Scaling up experiments of honeycomb catalysts for oxidation of hydrogen and methane gases

For a large volume air cleanup system in nuclear fusion facility honeycomb type oxidizing catalyst offers more useful advantage in terms of their low pressure drop than the conventional particle packed bed. Scaling up examination of 35 times large volume Pd catalyst deposit on metal honeycomb Al–Cr-steel alloy had been performed comparing with fundamental small size honeycomb. The catalyst was heated up to over 400 °C with stepwise by combined the inner and external heaters under various flow rate of processing gas containing various concentrations of hydrogen and methane. Then oxidizing reaction rates and the catalytic activation energies were evaluated and thermal property of catalyst bed was estimated considering exothermic oxidizing reaction in the process gas. As a result it was revealed that the scaling up honeycomb catalyst bed would be practically useful for the air cleanup system.     

Effects of water chemistry and potential distribution on electrochemical corrosion potential measurements in 553 K pure water

The effects of water chemistry distribution on the potential of a reference electrode and of the potential distribution on the measured potential should be known qualitatively to obtain accurate electrochemical corrosion potential (ECP) data in BWRs. First, the effects of oxygen on a platinum reference electrode were studied in 553 K pure water containing dissolved hydrogen (DH) concentration of 26–105 μg kg^?1 (ppb). The platinum electrode worked in the same way as the theoretical hydrogen electrode under the condition that the molar ratio of DH to dissolved oxygen (DO) was more than 10 and that DO was less than 100 ppb. Second, the effects of potential distribution on the measured potential were studied by using the ECP measurement part without platinum deposition on the surfaces connected to another ECP measurement part with platinum deposition on the surfaces in 553 K pure water containing 100–130 ppb of DH or 100–130 ppb of DH plus 400 ppb of hydrogen peroxide. Measured potentials for each ECP measurement part were in good agreement with literature data for each surface condition. The lead wire connecting point did not affect the measured potential. Potential should be measured at the nearest point from the reference electrode in which case it will be not affected by either the potential distribution or the connection point of the lead wire in pure water.     

Determination of emotional content of video clips by low-level audiovisual features

Affective analysis of video content has greatly increased the possibilities of the way we perceive and deal with media. Different kinds of strategies have been tried, but results are still opened to improvements. Most of the problems come from the lack of standardized test set and real affective models. In order to cope with these issues, in this paper we describe the results of our work on the determination of affective models for evaluation of video clips using audiovisual low-level features. The affective models were developed following two classes of psychological theories of affect: categorial and dimensional. The affective models were created from real data, acquired through a series of user experiments. They reflect the affective state of a viewer after watching a certain scene from a movie. We evaluate the detection of Pleasure, Arousal and Dominance coefficients as well as the detection rate of six affective categories. For this end, two Bayesian network topologies are used, a Hidden Markov Model and an Autoregressive Hidden Markov Model. The measurements were done using audio-only models, video-only models and fused models. Fusion is done using two different methods, a Decision Level Fusion and Feature Level Fusion. All tests were conducted using localized affective models, both categorial and dimensional. Results are presented in terms of detection rate and accuracy for affective families, affective dimensions and probabilistic networks. Arousal was the best detected dimension, followed by dominance and pleasure.     

Trap Levels in Eu and other Rare‐Earth Ions Codoped CaAl2O4 Phosphors

Photoluminescence spectrum, trap depths, and densities of trapped carriers of CaAl₂O₄:Eu phosphor crystals doped with rare‐earth elements were studied using the thermally stimulated luminescence technique. Trap depths and densities of the specimens vary with rare‐earth elements doped as the auxiliary activators. Tm and Nd are found to be effective for the strong afterglow phosphorescence peaking at λ = 442 nm for several hours after the excitation. CaAl₂O₄:Eu phosphor crystals doped with Nd and Tm include high density of carriers trapped at E = 0.59 and 0.52 eV, respectively.     

The lubrication mechanism in low speed plastic deformation with a synthetic lubricant — infiltration of lubricant into the boundary contact region

To investigate and evaluate the micro-pool mechanism in a mixed lubrication regime using polybutene lubricants, experiments were performed using 1 mm brass sheet, for various surface rough nesses of a work piece and die, lubricant viscosities and extrusion speeds. Systematic study showed that (1) the lower viscosity lubricant is easily squeezed out from the micro-pools into the flat are a through the troughs between the tool and work piece caused by plastic deformation of work piece, and (2) with decrease in lubricant viscosity and speed, or the larger the tool surface roughness becomes, the more lubricant infiltrates into the tool-work piece interface, which reduces the actual friction coefficient.     

Bactericidal effect of cationic hydrogels prepared from hydrophilic polymers

This study investigated whether hydrogels comprising hydrophilic cationic polymers have similar bactericidal effects. Bacteria were seeded on hydrogels and agar and their viability was assessed with time. Cationic hydrogels displayed bactericidal effects upon long-term bacterial contact. Furthermore, we assessed the areal density of cationic monomer unit of the cationic hydrogels, water content, and the initial elastic modulus. We examined correlations between each factor and bacterial death ratios; consequently, the bacterial death ratios were strongly correlated with the areal density of cationic hydrogel monomers. Elastic energy (W_el) generated at the cytomembrane ion-binding region and the cationic hydrogel and the cytomembrane interfacial energy (W_f) were estimated; consequently, W_el exceeded W_f at higher contact areas. The cationic hydrogel may extract cytomembranes with a reasonable adsorption area. Therefore, cationic hydrogels may be used as probes for ultrasonic echo to sterilize medical equipment.     

Effects of additives on sintering of CVD-MgO powders

The effects of a large number of sintering aids for the densification of magnesia were examined. Al₂O₃, BaO, Fe₂O₃, P₂O₅, SiO₂, TiO₂, Y₂O₃ and ZrO₂ are effective for the sintering of CVD-MgO powders at low doping levels. The effects of TiO₂ and ZrO₂ are significant. Heavy doping is harmful for densification. The eight oxides above are also effective for the sintering of seawater MgO, but the degree of effectiveness is smaller than for CVD-MgO. In the doping of BaO, P₂O₅, SiO₂ and TiO₂, which form eutectic liquids with MgO below 1600°C, there is an optimum firing temperature for densification.

Vickers hardness of doped MgO is proportional to the relative density and is unaffected by doping. Corrosion resistance of MgO ceramics for liquid PbO is also unaffected by dopants, except for P₂O₅.     

Application of magnetic pulse welding technique for flexible printed circuit boards (FPCB) lap joints

The magnetic pulse welding (MPW) is a high speed solid state welding process which has been used successfully to provide metallurgical and electrical bonds between flexible printed circuit board (FPCB) with using: (1) welding with aluminum driver sheet and (2) without driver sheet. The optimum bank energy for reliable bonding was about 1 kJ with 160–180 kA maximum current. The maximum tensile shearing for most welded samples was nearly same as tensile shearing strength of copper layer of FPCB sheet.     

Polymers used to influence cell fate in 3D geometry: New trends

The extracellular matrix (ECM) is a hydrogel-like structure comprised of several different biopolymers, encompassing a wide range of biological, chemical, and mechanical properties. The composition, organization, and assembly of the ECM play a critical role in cell function. Cellular behavior is guided by interactions that occur between cells and their local microenvironment, and this interrelationship plays a significant role in determining physiological functions. Bioengineering approaches have been developed to mimic native tissue microenvironments by fabricating novel bioactive hydrogel scaffolds. This review explores material designs and fabrication approaches that are guiding the design of hydrogels as tissue engineered scaffolds. As the fundamental biology of the cellular microenvironment is often the inspiration for material design, the review focuses on modifications to control bioactive cues such as adhesion molecules and growth factors, and summarizes the current applications of biomimetic scaffolds that have been used in vitro as well as in vivo.     

Single-molecular AFM probing of specific DNA sequencing using RecA-promoted homologous pairing and strand exchange

The specific sequence in a linearlized double-stranded DNA target has been identified at a single-molecular level by atomic force microscopy (AFM). This was accomplished using RecA-coated, single-stranded DNA probes which were paired with a specific complementary DNA sequence in a linear double-stranded DNA target by strand-exchange reaction at a homologous sequence site with target DNA. The sites of interaction between the nucleoprotein filaments and the double-stranded DNA targets were directly visualized by AFM in solution containing 4 mM magnesium acetate. Measurements of the position of RecA-coated probes paired to individual target DNA showed that DNA probes specifically paired at their corresponding homologous target sequences. Strand exchange promoted by RecA and the visualization by AFM provided a rapid and efficient way to identify homologous sequence on a single-molecule target DNA.